Jack



'J. C. KOPF.

J'ACK.

APPLICATION 'FILED OCT. 22. I919.

Patented A 5 1921.

4 SHEETS-SHEET L Ana/gun" J. c. KOPF.

' IACK.

APPLICATION FILED OCT. 22, 191

1,373,894. Patented Apr. 5,1921.

4 SHEETS-SHEET 2.

i 9 5a Fig.4.

/ ATTORNEY '1. 0. KOPF.

JACK.

APPLICATION FILED OCT. 22. 191 3.

. fitnted Apr. 5, 1921 4' SHEETS-SHEET 4.-

k MHMWH I A IN E/VTOR :5.

/ 7 ATTORNEY I UNITED S ES PATENT.

JOHN c. KOPIE, or BELLEVUE, PENNSYLVANIA, Assrenon TO THE DUFF MANUF C- QFFEE- TUBING COMPANY, OF PITTSBURGH, PENNSYLVANIA, CORPORATION 0]? PENN SYLVANIA.

- JACK. H 1,373,894 i "Specification of Letter s Patent. i v Patented Apr; 5', 1921,

Toallcvhomz't may concern:

Be it known that I, JOHN G. KOBE, a citizen of 'thelUnited States, and resident of the borough of 'Bellevue, in the county of Allegheny and State of Pennsylvania,'have invented a new and useful Jack, of which the following is a specification.

An object of the invention is to provide a simple, compact and serviceable self-locking rack and pinion jack. A furtherobject is to enable a jack of this description to be operated from a distance and at a convenient height. To these ends, the jack comprises a rack-bar, preferably. circular and free to turn in the stand, having downward-facing buttress teeth, and a convex spiral face pinion supported in tilted position in engagement with the rack,the axis of the pinion inclining upward and forward and being preferably prolonged by a long rotary detachable handle.

Still another object is to enable a selflocking operating pinion of a jack to be disengaged for quick-lowering, and'normally' and under load to be held securely in place. In the accompanying drawings, forming a part hereof: Figure 1 is a side elevation of the jack; Fig. 2 is a front elevation thereof, that is to say an elevation looking at the handle side;

Fig. 3 is a central vertical section taken in the plane of the axis of the pinion, showing the crank-handle with intermediate portions broken away;

Fig. 4 is a fragmentary" front elevation.

looking at the interior of the pinion case,

with the bonnet and pinion removed;

Fig. 5 is a horizontal section on the line 5-5 of Fig. 1; v

Fig. 6 is a transverse section taken on the angular line 6-6 of Fig. 3;

Fig. 7 is a face view of the pinion;

Fig. 8 is a vertical section illustrating a modification; and

Fig. 9 is a front elevation of Fig. 8.

The jack has an upright hollow columnar stand 2, with base 3. The interior of the stand forms a rack channel 4, circular in cross-section, for laterally supporting and guiding a round rack-bar 5 bearing a lifting seat 5 Said rack-bar is formed with circumferential rack teeth 6 of buttress formation, that is to say, triangular in chamber 9.

Application filed- October 22, 19191. SerialNu; 1332,512.

cross-section with sloping upper sides and approx mately horizontal orsquare under sides.

. Aseries of said teeth are meshedsimultaneously by a spiral buttressthread 7 on e a e f a tilted pin ondis his housed in a frame extensi0n'9 on the upper the disk is such in relation to this slope that all the convolutions in the upper part mesh with the rack teeth, while in the lower part the threads are out of engagement.

Thus, turning the pinion in one direction will exert a powerful raising pressure upon the rack, and with comparatively little friction owing to the line contact. The gearing is self-locking against descent, and, the rack being free to turn and present fresh portions of its teeth to the pinion, wear is distributed and minimized. The buttress form of the teeth and the engagement of a substantial number thereof at one time insures reat strength. 6

In the form of the invention illustrated in Figs. 1 to 6, the pinion 8 is secured on the inner end of an inclined driving shaft member 10, having a journal portion 11, which is rotatably supportedin a bearing 12 in a bonnet 13 screwed into the open end ofthe This construction permits of the ready assembling of the mechanism, the entrance which is closed'by the bonnet being large enough to admit the pinion. The pinion and shaft are held against axial displacement by a hub 14 and collar 15 embracing the bearing portion of the bonnet.

The pinion is directly supported against the load by an arcuate bearing ledge 16 formed on the bottom of the chambered frame portion 9, in position to constitute a res};I for the smooth circular periphery of the dis The outer end of the shaft member 10 has a cross-pin 17, or is otherwise formed, to re ceive the socket end 18 of a long detachable rotary crank-handle 19, which when in place extends upward to such height that the user can operate the jack from a distance and without getting close to the ground.

Figs. 8 and 9 illustrate a construction wherein a self-locking pinion for operating the rack-bar of a jack is displaceable at will, so that it can be disengaged to permitoi:

quick lowering in the absence of load. This 7 pinion is hinged at the bottom to the stand body 2 on a transverse pivot 20. A suitable readily-operated fastening 21, at the top, secures themovable frame part in the normal position, and permits it to be swung downward when desired. The relations "are such that with load upon the rack, the pressure of the rack teeth u on the thread of the pinion tends to draw t e pinion toward the racky and thus opposes'accidental disengagement when lifting.

1 In this construction the back wall of the case 9* is made integral; as the pinion can be placed upon the end of the shaft lfrom' within after the shaft has been through its bearing. 7

7 What I claim as new is: e A jack comprising a stand, a "rack-bar guided,thereinand'carrying a lifting seat,

and operating means comprising a tllted convex spiral face pinion mounted in the stand and'meshing at its upper part with the rack, the periphery of the pinion being inserted smooth and circular, and the stand having a'bearing beneath said periphery. 

